Temperature indicator



Qct. 12, 1943. w T, WELCH ETAL 2,331,750

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' TEMPERATURE INDICATOR Filed Dec, so, 1941 2 sheets-sheet 2 2a" /3 \i Y' null!! E W W. JZ. Jack'on,

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Patented Oct. 12, 1943` TEMPERATURE INDICATOR William T. Welch and William It. Jackson, New Orleans, La.

Application December 30, 1941, Serial No. 424,986

(Cl. 'i3-35S) 10 Claims.

The present invention relates to improvements in indicators and more particularly to devices for indicating a plurality of stages or conditions in sequence.

Inthe operation of many types of apparatus, such for example as electrical transformers, it is highly desirable to know the load under which the transformer is operating and to indicate when certain stages are reached. Attainment of such stages or conditions will be accompanied by a corresponding increase in temperature within the transformer or other apparatus.

An important object of the present invention is to utilize this increase in temperature to indicate the stage or condition which obtains in the apparatus.

Another object of the invention is to provide an indicator which may be set to indicate any desired stage or values within' the apparatus and which will then automatically and accurately indicate such conditions as they are reached.

Another object of the invention is to provide an indicator of this type which can be easily and rapidly reset for a new indicating cycle.

Still another object of the invention is the provision of a device of this character which is of simple construction, inexpensive to manufacture and install, and which is strong, durable and efcient in operation. Y

With the foregoing'and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the sev eral views,

Figure l is a front elevational view of a three stage indicator embodying the invention. r

Figure 2 is a side elevational view with parts broken away.

Figure 3 is a rear elevational view with parts broken away.

Figure 4 is a horizontal sectional view taken on the line 4 4 of Figure 2 and looking in the direction of the arrows.

Figure 5 is a sectional view taken on the line 5--5 of Figure 2, looking in the direction of the arrows.

Figure 6 is a similar view taken on the line 6-5 of Figure 2.

Figure 7 is a sectional view taken on the line 'I--1 of Figure 2.

Figure 8 is a vertical sectional view of a two stage indicator, parts being shown in elevation.

Figure 9 is a sectional view taken on the line 9 9 of Figure 8, parts being broken away and parts being shown in elevation, and

Figure 10 is a sectional view taken on the line IIJ-I0 of Figure 8, parts being shown in elevation.

Referring more particularly to the drawings, the numeral I I indicates a generally Vinverted vU-shaped support having one of its arms of substantially greater length than the other. The longer arm I2 of support II has an oifset lower portion I3 to which a casing I4 is rmly secured by welding or other suitable means. The shorter arm I5 of the support is provided with an offset lower portion i6 to which a signal housing II is secured by Welding or other suitable means. The casing I4 and 'housing Il are disposed on the outside portion of the arms, as best seen in Figure 2.

The housing Il is provided with a hinged cover I3 held in closed position by a spring latch I9. An elongated slot 2l] is provided in the bottom wall of the housing to receive an indicating flag strip 2I which is normally concealed in the cas ing with its lower end disposed in the slot 20, as shown in Figure 2. Shoulders 22 are disposed at the upper end of the ilag strip to prevent it from dropping completely through the slot 2U.

A guide tube 23 extends through a central opening in the top of housing Il, and follows the contour of the U-shaped support II on the outside thereof to a point substantially midway of the longer arm I2 where it is telescoped into the upper end of a covering hood 24 secured to the arm I2 and terminating at a point spaced above and in alignment with lthe center of casing I4. 'Ihe oifset portions I 3 and I5 of arms I2 and I5 are suiiciently offset to place the center of housing Il in line with the guide tube 23 and the center of casing IL'I in line with the center of the covering hood 24.

A slot 25 is disposed in the top of support II to receive the` top portion of the tube 23 so that the uppermost curved portion of tube 23 is substantially ilush with the uppermost curved portion of support II, as shown in Figures 1, 2 and 3. 1

A lsuitable wire or other flexible member 26 is secured to the top of flag strip 2| and extends through guide tube 23 and hood 24 to a point below the bottom of the hood, where it is secured to one end of a swivel or other connecting member 21.

The casing I4 is shown as circular in cross-section and is divided longitudinally into hinged sections, the main or body section being secured to arm portion I3 and the movable cover section 28- to the flag 2|'. In this construction two stages will be indicated by flag 2l' as the pellets melt. The entire device may be removed by unscrewing bushing 42, while the LA-shaped pipe with the casing lll' may be removed from the bushing 42 and casing 42' if desired. The device may be installed in the transformer at the factory or may be installed in transformers in use by the simple expedient of drilling an opening in the transformer wall to receive the bushing 4I.

A suitable Weather stripping 411 may be applied to the bottom of housings Il and Il to prevent clogging of slots 2i) and 2U by snow, sleet or the like. Although casing l is horizontally disposed, it will operate .in the same manner as the vertical casing I4 of Figure 1 due to the pull eX- erted on wire 33' by the flag strip.

In place of the gravity action of the flag strip y on the pellet carrying wire, suitable resilient means may be employed to bias the pellet carrying wire, Any desired number of pellets and discs may be employed and the pellets made of metal or other suitable material and may be made to melt at any desired temperature.

.It is obvious that various changes and modii'ications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:

l. In a signal device, a signal flag movable to a plurality of signalling positions and biased towards said signalling positions, a casing having a plurality of spaced abutments, a flexible restraining element connected to said signal iiag and extending into said casing, and spaced projections carried by said restraining element in alignment with the spaced abutments, one of said projections being in contact with one of the abutments to prevent movement of the signalling flag to signalling position, said projections being fusible at different temperatures and the spacing of the abutments and projections being such that when the projection contacting one of the abutments fuses, the restraining element and flag will move to a position where the next projection engages the next abutment, said first projection being fusible at a temperature lower than any succeeding projection.

2. In a signal device, a casing, a plurality of spaced abutments disposed in said casing, a signal iiag biased to move to a plurality of signalling positions, a flexible restraining element connected to said signal flag and extending into said casing in proximity to said spaced abutments, a plurality of spaced fusible projections fusible at different temperatures carried by the restraining element and adapted to engage the abutments, said abutments being spaced a greater distance apart than said fusible projections so that as a fusible projection is melted, the restraining element will move a substantial distance before the next fusible projection engages the next abutment, the projection contacting an abutment fusible at a lower temperature than any succeeding projection.

3. In a signal device, a substantially inverted U-shaped support, a housing carried by one arm of the support, a signal flag disposed in said housing and movable to a plurality of signalling positions, a casing carried by the other arm of said support, a plurality of spaced abutments in said casing, a flexible element connected at one end to said signal flag and extending around said support and into said casing past said abutments, a fusible projection carried bythe flexible element and engaging one of said abutments, a second fusible projection carried by said flexible j. element at a point spaced from said first fusible projection and spaced a substantial distance from the next abutment, said projections being fusible at different temperatures with the projection contacting an abutment fusible at a lower temperature than any succeeding projection, said signal flag being biased towards its signalling positions and restrained by engagement of the fusibleprojection with the adjacent abutment, said arrangement causing the second projection to move into engagement with the next abutment upon fusing of the first projection.

4. In a signal device, a substantially inverted U-shaped support, a housing carried by onearm of the support, a signal member disposed in said housing and movable to a plurality of signalling positions, a casing carried by the other arm of said support, a plurality of spaced abut-ments in said casing, a flexible element connected at one end to said signal member and extending around said support and into said casing past said abutments, a fusible projection carried by the flexible element and engaging one of said abutments, a second fusible projection carried by saidflexible element at a point spaced from said first fusible projection and spaced a substantial distance from the next abutment, said signal member being biased towards its signalling positions and restrained by engagement of the fusible projection with the adjacent abutment, said arrangement causing the second projection to move into engagement with the next abutment upon fusing of the first projection, said second projection being fusible at a higher temperature than the first projection. v

5. In a signal device, a substantially inverted U-shaped support, a housing carried by one arm of the support, a signal member disposed in said housing and movable to a plurality of signalling positions, a casing carried by the other armof said support, a plurality of spaced abutments in said casing, a flexible element connected at one end to said signal member and extending around said support and into said casing past said abutments, a fusible projection carried by the flexible element and engaging one of said abutments, a second fusible projection carried by said flexible element at a point spaced from said first fusible projection and spaced a substantial distance from the next abutment, said signal member being biased towards its signalling positions and restrained by engagement of the fusible projection with the adjacent abutment, said arrangement causing the second projection to move into engagement With the next abutment upon fusing of the first projection, said second projection being fusible at a higher temperature than the first projection, and a guide tube carried by the support and slidably receiving the flexible element.

6. In a signal device, a substantially inverted U-shaped support, a housing carried by one arm of the support, a signal member disposed in said housing and movable to a plurality of signalling positions, a casing carried by the other arm of said support, a plurality of spaced abutments in said casing, a flexible element connected at one end to said signal member and extending around said support and into said casing past said abutments, a fusible projection carried by the flexible :element amd engaging :one ci said abutments, a .second fusihle projection -canried iby said :flexible element :a epoint spaced ifrorn said rst fusible projection and espaceid a "substantial distance;from fthe mext tabntrnent, said .signal member rbeing .'tiiaseld :towards its lsignalling positions and restrained byengagement of thefusiblelprojection 'with the vadjacent :abutment said arrangement causing `the 'second .projection :to .move -into 'engagement 'with .the 'next abutment `-upon. fusing tod :the rst projection, :said second :projection `being :tusilole -at 'la higher temperature than Ithe fiirst projection, said -abutments comprising :partitions .dividing said casing-and havingaligned openings 5to :slidably receive the flexible ielement.

7. :In ma :signal device, :a lsupporting `Wall having fen fopening extending therethrough, 'la :guide Atube :extending through -said opening, fa Acasing married by said .tube -on .one side of :the xwall, a housing disposed 4adda-:nent fthe other fend of the :tubefon fthe-.otherside .of the Wall, :a signal inember `in said housing and having :a plurality of signalling gpos'rtions, a lpluralityvof spaced :abut- {ments disposed in fsaid casing, fa fflexible :element connected to the signal `member and 'extending through :said ftube fandinto said casing past said abutnrents, .a fusible projection :carried by the exible 'element -and engaging one of said abutments,asecond fusible proj ectionhavinga higher ltusible temperature than the :first mentioned pro- ',jection aon Ythe ilexibleelement and spaced from said .'rst projection and -f-rom the 1next adjacent abutment, said :signal .member being biased toward .its signalling positions :and 4restrained :by

engagement `of .the fusible projection with the 1 adjacent 4fabutrnent so 'that Whenrsaid iii-st pro- ,jeotion is :fused the :second 'projection lwill -move intoengagement with the nextfabutment.

28. ,In sa signal device, fa supporting `vvall .having an opening extending therethroughsaguide .tube extending through fsa-idopening, fa -casing .carried by :said .tube ion one .side of lthe ovall, a housing disposed Iadjacent :the other end ofthe Atube on the .fother Vside Iof the Wall, -a .signal member -in said housing 4and having a I:plurality-of signalling positions, a plurality lof Vspaced abutments .fdisposed in said casing, a -ilexible element connected to the signal :member fand extending Ithrough said tube iand into said rcasing past said abutment-s, a `fusible projection carriedrbythevlexiblefelement and engaging -one zof said labutmentd :a :second fusible projection -on the 'flexible 'element and spaced -from said .'rst ,projection and vfrom :the next adjacent abutment, rsaid signal member being biased Atoward 'its signalling Ypositions fand restrained by engagement iof the :fusible yprojecassenso tion with the :adjacent abutment eso that -lwhen said first projection lis fused the vsecond pro'je'ction `will move finto :engagement with the next abutment, saidirst projection `being fusible at ia lower temperature than the .second projection, said Aabutments vcomprising Jpartitions dividing said :casing fand having aligned openings 4to slidably V,receive .thezfiexibleselement i9. In :a .signal device, -a :substantially :inverted U-shaped support, .a housing vcarried by Aonearrn of .thessupport a Asignal member :disposed in said housing and movable to n plurality .of signalling positions, a .casing Icarried by the other arm `of said support, a plurality 'of spaced abutments in said casing, :a exible element 'connected at :one end :to said :signal :member 'and extending around said support andfinto said `casing past .said abut- -ments, a fusible projection carried by the exible element andengaging one of said 'abutments :a second fusible lprojection vcarried by said flexible element :at a .point spaced from said first :fusible proj eotionand spaced a 'substantial'distance from the next abutment, said 'signal .member 'being biased towards its signalling positions and :11estrained Aby 'engagement ofthe iusible projection with 'the adjacent abutment, said arrangement `causing the lsecond projection Yto move into engagement vvithzthenext abutment upon iusingfo the rst projection, 'said 'second projection being fusible at a higher temperature `than the rst projection, said abutments comprising partitions dividing said casing and having :aligned openings to slidably `receive :the flexible element, there being openslots leading frornone -edgeof-eaohfpartn tion into `the opening atherein, said slots of the .partitions being disposed in alignment, and means tolopen and close theportionrofthe casing'covering the open ends ofthe partition slots.

1.0. Ina signal device, a '.casing, -a plurality of spaced abutmentsdisposedin said casinga lmovable element extending into the casingy fa fusible projection carried by said movable element and engaging one .of rsaid'abutments to hold said element against movement through the casing, la second projection fusible at a higher temperature than the first mentioned .projection `carried 4by said ymovable .element'in alignment 'withzthenext abutmentbut spaced a substantial distance therefrom, and a 'signalflag carried bvsaid movable element Wherebywhenltheirst mentioned projection fuses the movable .element .and flag will move until the .second .projection engages the next abutment. 1

WILLIAM T. WELCH. 'WILLIAM 1R. JACKSON. 

